Wafer binding method and apparatus

ABSTRACT

The present invention relates to a method and an apparatus for automatically binding a silicon wafer to a carrier plate. In the binding method of the present invention, the wafer is positioned underneath the carrier plate and then lifted and bonded to the carrier plate, at or below atmospheric pressure: once this is accomplished the process returns to the previous pressure. In addition, in the apparatus which performs this process, by means of a carrier means which supplies the carrier plate and wafer to the location where binding is to be carried out, the binding surface of the carrier plate and wafer are turned upward, transported and the carrier plate is flipped around in the interval between the carrier plate transportation apparatus and the binding unit.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an apparatus for binding a carrierplate, used in a silicon wafer polishing apparatus, to a silicon wafer.

2. Prior Art

In the polishing of a monocrystal silicon wafer (hereafter referred toas just "wafer"), a fixed carrier plate is bonded to a plurality ofwafer sheets: this carrier plate is then casted into the polishingapparatus and the polishing of the wafer is carried out.

In the prior art disclosed in First Publication Laid open number63-245366, when a wafer is being bonded to the aforementioned carrierplate, wax has been previously applied to the inside of the wafer as abinding agent. A plurality of wafers are then placed on top of thecarrier plate and after adhesion, the bonding was carried out using apressure binding apparatus, as shown in FIG. 36.

In this apparatus on top of the main frame 80, inside the pressurelowering chamber 81, a press plate 83 is provided. To begin with acarrier plate 91 is placed on top of the pedestal 85, and restingdirectly above that is a press plate 83 for applying pressure to thewafer 90. At that time, while pressure is being lowered inside thepressure lowering chamber 81, which includes both the carrier plate 91(on top of the pedestal) and the press plate 83, pressure is beingapplied to the wafer by the press plate 83. Following the deaeration ofthe binding surfaces of the wafer 90 and the carrier plate 91, thepressure lowering chamber 81 is returned to normal pressure and thebonding can then be carried out without the existence of air bubblesbetween the wafer and carrier plate.

However, the minimum line width of the integrated circuit (IC) used inthe silicon monocrystal is 1 μm. Additionally, when trying to form acircuit using optical lithography, due to the shallow depth of focus, awafer possessing a satisfactory flatness is required. In order to obtainthis desired wafer, improvements in both the polishing process as wellas in the controlling of the carrier plate flatness are being carriedout. There exist additional problems however, during the bonding, in thethickness and the thickness distribution of the wax layer: the wax layerthickness can be no greater than 1 μm. Furthermore, there were alsodrawbacks in that refuse was entering into the space in between thecarrier plate and the wafer as well as air bubbles were being leftbehind creating unwanted "dimples" on the surface of the wafer followingthe polishing. Deterioration of the ability to flatten the carrier platealso was a point of concern.

In the bonding procedure of the prior art, when the aperture of thewafer becomes as big as 200 mm φ, the uniform application of pressurebecomes difficult. Additionally, when the wafer to which wax has beenapplied is facing downward, the occurrence of refuse cannot be ignoredbecause a significant problem arises even when small particle refusegets in between the wafer and carrier plate.

SUMMARY OF THE INVENTION

An object of the present invention is to, when a plurality of wafers arebeing bonded to a surface of the carrier plate, reduce the thickness ofthe wax and uniformly distribute the layer in addition to reducing theoccurrence of unwanted dimples while at the same time obtaining adesirable flatness. It is also an object of the present invention toprovide for both the automatic supply and withdrawal of the carrierplate, wafer and wafer carrier to the binding apparatus.

The present invention, order to obtain the above mentioned objectives,performs the binding of the wafer to the carrier plate through a seriesof steps. In the first step, the wafer, the upper surface to which abinding agent has been applied (the surface of application of theaforementioned binding agent is turned facing upward) is positionedunderneath the carrier plate. When the upper surface of theaforementioned wafer and the underside of the carrier plate are arrangedopposite, facing each other, the surrounding pressure is no greater thanthe atmospheric pressure. In the next step the aforementioned waferrises and binds to the aforementioned carrier plate. Finally once thewafer and carrier plate are bound to each other, the pressure of thesurrounding environment is raised and returned to normal levels.

Through this kind of organization, there is no air disturbance on thebinding face because the binding of the wafer and the carrier plate canbe performed under reduced pressure. Consequently, the occurrence of airbubbles on the binding face can be prevented and even if the aperture ofthe wafer is large, the occurrence of dimples is reduced. Additionallyas previously mentioned, the binding is carried out under reducedpressure conditions such that the binding face is not disturbed by theair. Moreover, since normal pressure is returned to slowly, uniformpressure is more effectively applied and the thickness of the waxbecomes uniform. Furthermore, there is no rolling about of the wafersurface to which has been applied and the adhesion of refuse is rare sothe undesirable occurrence of dimples is reduced and consequently, awafer with a desirable flatness can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the pipe system of the binding apparatus of the preferredembodiment.

FIG. 2 is a cross section of the principle parts in the bindingapparatus.

FIG. 3 is an enlarged cross section of one part of the bindingapparatus.

FIG. 4 is a top view of the wafer carrier.

FIG. 5 is a exploded diagram showing the position relations of the wafercarrier and the wafer.

FIG. 6 is an enlarged plane view of one part of the wafer carrier.

FIG. 7 is a flow chart of the actions carried out by the binding unit.

FIG. 8 is a plane view showing the layout of the binding apparatus.

FIG. 9 is a front view of the carrier plate stock part.

FIG. 10 is a side view of the fixed frame and the moving frame.

FIG. 11 is a side view of the washing apparatus.

FIG. 12 is a front view of the washing apparatus.

FIG. 13 is a cross section of the bearing part of the washing apparatus.

FIG. 14 is a plane view of the transport apparatus provided in thewashing apparatus.

FIG. 15 is a plane view of the transport apparatus provided in thewashing apparatus.

FIG. 16 is a plane view of the drying apparatus.

FIG. 17 is a front view of the drying apparatus.

FIG. 18 is a plane view of the transport apparatus provided in thedrying apparatus.

FIG. 19 is a front view of the transport apparatus provided in thedrying apparatus.

FIG. 20 is a plane view of the heating apparatus.

FIG. 21 is a side view of the heating apparatus.

FIG. 22 is a cross section of the transport apparatus provided in theheating apparatus.

FIG. 23 is a cross section view of the main part of the transportationapparatus from FIG. 22.

FIG. 24 is a cross section view of the axial part of the heatingapparatus.

FIG. 25 is a plane view showing the layout of the binding unit and itssurrounding apparatus.

FIG. 26 is a front view of the parts shown in FIG. 25.

FIG. 27 is a side view of the parts shown in FIG. 25.

FIG. 28 is a side view of the wafer transportation machine.

FIG. 29 is a plane view of the working beam.

FIG. 30 is a side view of the working beam.

FIG. 31 is a cross section view of the centering apparatus.

FIG. 32 is a cross section view of the washing apparatus.

FIG. 33 is a cross section view of the wax coater.

FIG. 34 is a plane view of the machine surrounding parts in OF position.

FIG. 35 is side view of the parts shown in 34.

FIG. 36 is a cross section view of a prior art binding apparatus.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

An explanation on the binding unit provided in the wafer apparatus ofthe present invention is given by referring to FIG. 1 to FIG. 7.Furthermore, in the explanation following hereafter, when using the wordwafer, a wafer before polishing is referred to.

The wafer binding unit 1, shown in FIG. 1 (hereinafter simply calledbinding unit) is substantially constructed by pedestal 4, which isplaced on main frame 10, wafer carrier 5, which is supported by pedestal4, and by press plate 3, which is hung up so that it can be moved up anddown by driving cylinder 31 located above. Pedestal 4, wafer carrier 5and press plate 3 are contained within cover 21 which opens and closesand goes partly up and down with the movement of press plate 3. Whencover 21 descends and closes up to the upper surface of main frame 10,the inner part of cover 21 becomes a first decompression chamber 2 whichmaintains air-tight conditions. This first decompression chamber 2 isdeaerated via a first ventilation line L1 which is on line with apressure control system, and vacuum conditions are created inside thisfirst decompression chamber 2. On the other hand, on the inside ofpedestal 4, placed on top of main frame 10, a second decompressionchamber 49 is formed, and a second ventilation line L2, which is inseries with the aforementioned pressure control system and penetratespartly main frame 10 and pedestal 4, is provided and gives a possibilityfor deaeration.

In the present invention, as indicated in FIG. 2, aforementioned firstdecompression chamber 2 and second decompression chamber 49 are dividedby diaphragm 41 provided horizontally in the inner part of pedestal 4and providing the possibility for controlling each pressureindependently. Furthermore, above aforementioned diaphragm 41 wafercarrier 5 maintaining a plurality of wafers 6 and carrier plate 7 bondedto the latter, are placed at a fixed position on this pedestal 4. Asshown in FIG. 5, at wafer carrier 5, wafer supporting part 51c isprovided and supports the plurality of wafers 6 at a position oppositethat of the upper surface of diaphragm 41. Furthermore, a carrier platesupporting plane 51b is formed and supports carrier plate 7 at aposition which is of a fixed distance from the upper surface of wafer 6.In such a construction, first decompression chamber 2 and seconddecompression chamber 49 are equipped with pressure control meanscontrolling the pressure therein; first decompression chamber 2 andsecond decompression chamber 49 are both decompressed by aforementionedpressure control means; second decompression chamber 49 has a higherpressure relative to first decompression chamber 2; diaphragm 41 isshifted towards carrier plate 7 at a distance greater than the fixedspacing.

Hereinafter, a detailed explanation on the main preferred embodimentfollows.

Pedestal 4 placed on main frame 10 is formed in a plane round shape andintegrates the metal plateau of the lower part, where the inner part washollowed out to form a flat bowl, and the upper part frame body of thering. The round and thinly shaped diaphragm 41 is clasped between theupper part frame body and the lower part of the metal plateau. At theclasp part of diaphragm 41, as shown in FIG. 3, the main frame innerdiameter of the upper part is taken a little larger than the metalplateau inner diameter of the lower part of pedestal 4, and forsupporting the base periphery of wafer carrier 5, which is placed onthis pedestal 4, diaphragm 41 is clasped and formed at the part of thedifferent diameters. Diaphragm 41 consists of a membrane body havingelasticity and is made from rubber or synthetic rubber, and can deformaccording to the pressure difference between the upper and lowersurface. Thus, the first decompression chamber 2 is divided by diaphragm41, which is clasped in the inner space of pedestal 4, and seconddecompression chamber 49 is formed inside the lower part of the metalplateau.

Wafer carrier 5, which is generally disc-shaped on the outside forsupporting the plurality of wafers 6, and carrier plate 7 is put insidethe upper part of the frame body of aforementioned pedestal 4, and thelower surface of the latter is close to contacting with the uppersurface of diaphragm 41.

Next, this wafer carrier 5 supports the plurality of wafers 6 andcarrier plate 7, is considered to be conveniently dealt with, is made ofaluminium or an aluminious alloy, has a membrane coating for smootheningits surface, and was galvanized. In FIG. 4, the upper side of wafercarrier 5 in which wafers 6 are positioned as shown, and to make itpossible that the plurality of wafers 6 are equidistantly positioned,wafer insertion holes 51 are provided. The upper surface becomes carrierplate supporting plane 52 for supporting carrier plate 7 above diaphragm41 at a fixed distance from aforementioned diaphragm 41.

When passing approximately half way round the upper surface periphery atwafer carrier 5, and when putting carrier plate 7 on carrier platesupporting plane 52, carrier plate guidance 53, which is the standing uppart for fixing the position, is formed as one body in wafer carrier 5.The guiding notches 56 provided at two locations in FIG. 4 are thesupporting parts in case when wafer carrier 5 is installed on, orremoved from pedestal 4, and further makes it easier to install andremove carrier plate 7 to wafer carrier 5. Furthermore, an insertionhole kerf 54, is connected at the carrier plate supporting plane 52, andevery wafer insertion hole 51, with the outer space of wafer carrier 5,is grooved in: these insertion holes 51 become the communication systembetween the upper surface aperture of wafer 6, inserted in waferinsertion hole 51, and the outer space of wafer carrier 5.

Angle chamber 51b is formed at the opening periphery of the waferinsertion holes which are supplied in plurality at carrier platesupporting plane 52 of wafer carrier 5, as indicated in FIG. 5 and 6, inorder to make it possible that wafer 6 is easily mounted thereon. At theinner wall of wafer insertion hole 51, a plurality of wafer supportingparts 51c are provided so that wafer 6 can be supported at a loweredposition in contrast to carrier plate supporting plane 52. Wafersupporting parts 51c are formed as a plurality of protrusions relativeto the upper part of the inner wall of wafer insertion hole 51 byproviding missing parts 51e: since these parts are left over around thecircumference and located at fixed intervals in the upper part of theinner wall of wafer insertion hole 51, they are in the same verticalplane as the inner wall of insertion hole 51 in downward direction.

Thus, due to the level difference between carrier plate supporting plane52, supporting carrier plate 7, and wafer supporting parts 51c, whichsupport wafer 6, the fixed space interval between wafer 6 and carrierplate 7 to which the wafer is adhered, can be guaranteed. Whenconsidering the deaeration efficiency and the displacement value ofdiaphragm 41, the space interval between wafer 6 and carrier plate 7should be as little as possible, for example most preferably in therange of 1 mm to 5 mm, so that there is no direct contact.

Aforementioned insertion hole kerf 54 is grooved out a little deeperthan the upper surface of wafer supporting part 51c, and missing part51e which is supplied at the upper part on the inner wall of waferinsertion hole 51 makes it possible that upper surface cavities of wafer6 can communicate with the gaps occurring at the lower surface. This isfor creating identical conditions for the lower and upper surface ofwafer 6 at the time of deaeration of the first decompression chamber 2.

Wafer pressing plate 55 is attached to wafer insertion hole 51 whichopens at carrier plate supporting plane 52. For this case, a pluralityof nail notch supports 51a (at four places in the same figure)distributed in equal space intervals on the opening periphery of waferinsertion hole 51 are provided with a constant depth, so that pressplate support nail 55a notched on wafer pressing plate 55 can beinserted therein.

Wafer pressing plate 55 is for lifting wafer 6 from its lower surfaceand pressing it up against carrier plate 7: the pressing plate 55 ismade of such materials as silicon rubber, fluorine resin, ultrahighmolecular polyester or materials which do not damage the surface ofwafer 6 and further have the property of being friction resistant. Thelower surface of the pressing plate 7 directly contacts the uppersurface of diaphragm 41 and thickness is provided so that pressing side55b in FIG. 5, rests on wafer supporting parts 51c. In other words, theupper surface of wafer pressing plate 55 almost comes in contact withthe lower surface of wafer 6. However, in order to enable wafer pressingplate 55 to move freely up and down inside the tube of wafer insertionhole 51, it is loosely fit into the horizontal plane defined byaforementioned pressing plate support nails 55a and nail notch supports51a.

At the lower surface of wafer carrier 5, as indicated in the A--A crosssection view of FIG. 6(b), angle chamber 51d is provided at the lowersurface opening part circumference of wafer insertion hole 51. Whenwafer carrier 5 is placed on the upper portion of the frame body ofpedestal 4, the upper surface of diaphragm 41 contacts the base of waferpressing plate 55 which is attached to the base of wafer carrier 5 andwafer inserting hole 51. However angle chamber 51d is provided forassuring the necessary shift value when diaphragm 41 is dislocated inupward direction and for pressing sufficiently wafer pressing plate 55against carrier plate 7. Considering the arrangement of all theconstruction members, the wafers as well as the carrier plates adheringto the wafers, in the inner part of pedestal 4 fixed on top of mainframe 10 there is a second decompression chamber 49 formed and dividedby diaphragm 41, and above this aforementioned diaphragm 41, wafercarrier 5 is located and contacts the upper surface of diaphragm 41.Furthermore, wafer pressing plate 55 is attached to wafer insertion hole51 which opens at wafer carrier 5, and this base forms a plane nearlyidentical to the base of wafer carrier 5 and further contacts the uppersurface of diaphragm 41. On the other hand, wafer 6 is located on top ofwafer supporting part 51c of wafer insertion hole 51. Wafer supportingpart 51c is positioned a little lower than carrier support plane 52, andthe position of wafer 6 is also below the carrier plate support plane 52of wafer carrier 5. Wafer carrier 7 is supported by carrier platesupporting plane 52 which contacts wafer carrier 7 above wafer carrier5.

In other words, wafer carrier 5 supports wafer 6 through wafersupporting part 51 at a position above diaphragm 41 and facing the uppersurface of diaphragm 41. Wafer carrier 5 supports carrier plate 7 bycarrier plate supporting plane 52 at a position between wafer carrier 5and upper surface of wafer 6 at a fixed space interval. In connectionwith the explanation on pressboard 3 and cover 21 it should by mentionedthat pressboard 3 which is pressed against the upper surface of carrierplate 7, which is attached to the upper part of wafer carrier 5, isinstalled such that it can move up and down. In the present inventionthere is n need for putting positive pressure on pressboard 3, and therising of plate 7 can be prevented when pressure is applied to the uppersurface of plate 7 by pressplane 33.

As shown in FIG. 3, at the upper part of cover 21 a rod sheath 22 isprovided. A cylinder rod 32 passes through this rod sheath 22, in linewith driving cylinder 31 of pressboard 3. Air tight sealing is attainedby O-rings 23 contacting the inner surface of rod sheath 22 and theouter surface of cylinder rod 32, which also provides the possibility ofsliding contact. At the lower end of cover 22 flunge 25 is formed. Whenlowering cover 22, the lower surface of flunge 25 contacts the surfaceof main frame 10, whereby airtightness is assured by O-ring 24 , andthus, first decompression chamber 2 formed inside aforementioned cover21 is shut tightly. When wafer 6 and carrier plate 7 are taken out andput in, the lower end of rod sheath 22 is supported by flange 34, whichis used as a connection of pressboard 3 and cylinder rod 32, and whenpressboard 3 is lifted up, also cover 21 goes up and the upper surfaceof main frame 10 is opened.

For the up and down movement of pressboard 3 air or oil pressure drivingmeans, not shown in the figure, are used, and sensors and limit switchesfor determining the position of the actuators, as well as such things astimers for setting the time of the action process are provided.Furthermore, the up and down movement of press plate 3 is controlledwith a pressure system by a control apparatus utilizing program controlequipment.

Explanations on the pressure control means of the main equipment aregiven with reference to FIG. 1.

First ventilation line L1 leading to the first decompression chamber 2provides a vacuum meter PI1 measuring the vacuum in the firstdecompression chamber 2 and is connected to pipe L6 leading to vacuumpump 12 via three way manifold valve SV3. Furthermore, secondventilation line L2 leading to the second decompression chamber 49 isconnected to pipe L4 via adjustment valve V6 and having a branch in themiddle. The other side of aforementioned pipe L4 is divided by valve 2and connected to aforementioned first ventilation line L1. At pipe L4vacuum meter PI2 which measures the vacuum density in the seconddecompression chamber 49 is attached, accumulator 11 easing suddenpressure changes is provided, and on the other side aforementioned pipeL4 is connected via valve SV1 to pipe L3. This pipe L3 is closed andopened to the atmosphere by adjustment valve V5 on the other end.Pressure switch 13 for controlling the closing and opening of valves SV1and SV2 is installed at accumulator 11. The opening on the other end ofaforementioned three way manifold valve SV3, which divides firstventilation line L1 and pipe L6 is connected to pipe L5 which closes andopens to the atmosphere via adjustment valve V7. Furthermore, pipe L6leading to vacuum pump 12 provides a branch in its mid-section. Fromthis branch pipe L6 is connected to pipe L7 which connects this branchvia valve SV4 to the open atmosphere.

In the aforementioned pipe system, air pressured or electromagneticdiaphragm valves or butterfly valves may be used. Furthermore, as anadjustment valve V6 may serve a flux control valve such as a bellowtaking into account inner part leakages. By these pressure control meansdecompression is performed in the first decompression chamber 2 andsecond decompression chamber 49, both located in the main equipment, andfurthermore, second decompression chamber 49 may be overpressured inrelation to first decompression chamber 2.

The action of binding unit 1 in the preferred embodiment is explained byreferring to the process chart displayed in FIG. 7.

First, pressboard 3 and cover 21 are caused to have a lifted standbycondition by the operation of the pressboard driving system (not shownin the figure). the upper surface of main frame 10 is opened, wafercarrier 5 where wafer 6 is located is placed on pedestal 4, and carrierplate 7 is placed on the upper part of waver carrier 5 (step 101). Thenthe operation of the equipment is started, by lowering pressboard 3cover 21 is lowered and sticks to the upper surface of main frame 10(step 102). Pressboard 3 is further lowered, and press plane 33 is movedto the position until it directly contacts the upper surface of carrierplate 7 and then stops (step 104).

While cover 21 is fixed, the first decompression chamber 2 and seconddecompression chamber 49 are connected to the piping system which isconnected to vacuum pump 12 and the decompression is started (step 103).At this time, vacuum pump 12 is in action, valves SV1, SV4 are closedvalve SV3 closes pipe L5, valve SV2 is open and first decompression 2and second decompression chamber 49 are both deaerated via firstventilation line L1 and second ventilation line L2. Then, firstdecompression chamber 2 and second decompression chamber 49 aredeaerated below the pressure of 1 mmHg (step 105).

Then valve SV2 is shut, valve SV1 is opened, air enters via pipe L3, andthe pressure in the second decompression chamber 49, which is ventilatedfrom the second ventilation line L2 and connected to pipes L4 and L3, isgradually increased. By the pressure increase of the seconddeccmpression chamber 49 diaphragm 41 is lifted up, and wafer 6 ispressed against the lower surface of carrier plate 7 by wafer pressingplate 55 (step 107). The decompression status is continually maintainedfor the first decompression chamber 2 (step 106). When the pressure inthe second decompression chamber 49 is increased to a value between 300mmHg and 400 mmHg, pressure switch 13 of accumulator 11 actuates andvalve SV1 shuts. Only the pressure of the second decompression chamber49 is maintained at the aforementioned condition, and during this perioda pressure on wafer 6 is maintained (step 108). Once wafer 6 is pressedagainst carrier plate 7, the applied wax causes it to stick to the lowersurface of carrier plate.

Valve SV2 is opened and pipe L4 is connected to the first ventilationline L1, pipe L6 and vacuum pump 12. The second decompression chamber 49again is decompressed and put to equal pressure with first decompressionchamber 2. By this, diaphragm 41 goes down to restore the original state(step 110). After that, valve SV1 and valve SV3 leading to pipe L5 areopened, and the pressure in the first decompression chamber 2 and seconddecompression chamber 49 is simultaneously increased to atmosphericpressure (step 111). When first decompression chamber 2 goes back toatmospheric pressure wafer 6 sticks to carrier plate 7.

Then press plate 3 is lifted up (step 112) and along with press plate 3cover 21 is lifted up and the upper surface of main frame 10 is opened(step 113). Thereafter, carrier plate 7 to which wafer 6 is adhered istaken out (step 114).

When the job is started vacuum pump 12 is caused to operate for thefirst time in step 103, but when continually entering the next batch, itis possible to return to step 101 while vacuum pump 12 is operating.When the job is terminated, vacuum pump 12 is stopped after valve SV4has been opened. Furthermore, the operational binding unit 1 moving insuch a way along with the driving system of a normal pressboard iscontrolled by an identical control apparatus and automated.

Next, a plurality of wafers 6 above diaphragm 41 are kept in a positionfacing the upper surface of diaphragm 11. Carrier plate 7 is maintainedat a position facing the upper surface of aforementioned plurality ofwafers 6 at a fixed interval there in between.

At the beginning first decompression chamber 2 and second decompressionchamber 49 are simultaneously decompressed. When first decompressionchamber 2 is deaerated, also the air in the cavity of wafer 6 andcarrier plate 7 is sucked out. Thereafter, while the decompressed statusof decompressed chamber 2, second decompression chamber 49 isoverpressured relative to first decompression chamber 2 by causing thepipe system to leak through the second decompression chamber 49. Whendong this, the pressure difference between first decompression chamber 2and second decompression chamber 49 causes the elastic diaphragm 41 toshift for a fixed interval in upward direction of carrier plate 7 of thefirst decompression chamber 2. Wafer 6 is pressed via wafer pressingplate 55 of wafer carrier 5, which is put in the upper surface ofdiaphragm 41, against the lower surface of carrier plate 7. Wax is puton the backside of the wafer (upper surface inside the equipment), andby this wax wafer 6 is carried by the lower surface of carrier plate 7.Thereafter, first decompression chamber 2 and second decompressionchamber 42 are equalized, diaphragm 41 is put into its startingposition; and when first decompression chamber 2 and seconddecompression chamber 49 are opened to the atmosphere, wafer 6 ,carriedby the lower surface of carrier plate 7, is uniformly covered with waxby applying hydrostatic pressure: since no air reaches this bindingplane, dimple impurities due to occurrence of air bubbles are prevented.

Another advantage of the present invention lies in the wafer bindingused in the aforementioned wafer binding unit. In other words, the uppersurface of the wafer and the carrier plate binding it are arranged at aposition of fixed interval, facing each other and are allowed to betreated under reduced pressure. A plurality of wafers is simultaneouslylifted from its lower surface and bound to the carrier plate.Thereafter, a pressure increase is carried out.

Binding part 1 is explained hereafter. At the first decompressionchamber 2 a plurality of wafers 6 and carrier plate is positioned.Aforementioned wafer carrier 5 is used so that wafer 6 and carrier plate7 maintain a fixed position relation. In other words, the plurality ofwafers 6 and carrier plates 7 are positioned so that they face eachother and the interval there in between lies in the range of 1 mm to 5mm. The first decompression chamber 2 is decompressed below 1 mmHg. Thenthe plurality of wafers 6 are simultaneously lifted up to carrier plate7 and pressed to bind. Wax, wherein rosin is added to a parafinic resin,is beforehand applied on wafer 6 or carrier plate 7, and by means ofthis wax, wafer 6 is carried by carrier plate 7. In this state, when thefirst decompression chamber 2 is pressured up until atmosphericpressure, wafer 6 is bound to carrier plate 7.

Binding is carried out by this binding part, and the LTV smoothness islower than 0.5 μm in an area of 20 mm×20 mm on polished wafer which hasa diameter of 200 mm. When polishing was performed under the samepolishing conditions in prior art binding parts, LTV smoothness was ±1.0μm, and thus the improvement is obvious.

In the aforementioned binding part of the present invention wafer 6 ispressed against carrier plate 7 by the shifting of diaphragm 41, andwith regard to the effective use of the decompression means the transferis performed in the upward direction of wafer 6 by the pressuredifference between the first decompression chamber 2 and the seconddecompression chamber 49. However, for example, it is possible to pressthe wafer against the carrier plate by using such things as a tablemoving up and down the plane by means of a driving cylinder which isable to move in vertical direction under decompression.

In binding part 1 a wafer press board 55, which operates indirectly viadiaphragm 41 against the lower surface of wafer 6, is attached to wafercarrier 5. This aforementioned press board 55 is designed for shiftingpressure in an upward direction in order to stabilize wafer 6, thoughthe supporting means for keeping wafer 6 and carrier plate 7 at a fixeddistance may be of different shape. It is also possible for the uppersurface of diaphragm 41 to come in direct contact with the lower surfaceof wafer 6.

Since the present invention has the aforementioned construction, theeffects stated hereafter may be listed.

1. The fixed interval between the wafer and the carrier plate isdeaerated by decompression, and when a direct contact forms a bindingplane under decompression, it is impossible that air penetrates therein.Accordingly, the occurrence of air bubbles on the binding plane can beprevented, and dimple impurities can be limited even on wafers with abig diameter.

2. As mentioned before, binding is achieved under decompression wherebypenetration of air into the binding plate is prevented, and since thereis a gradual return to normal pressure, a more uniform pressure can beobtained and wax can be distributed to a more uniform thickness.

3. Because the wafer to one side of which wax was applied cannot beturned over, and because the adhering amount of refuse is decreased, theoccurrence of dimples is also decreased.

4. For the shift-up of the wafers the same pressure control system isused for the decompression chambers. Accordingly, it is not necessary touse other driving means for the shift-up and the apparatus constructionmay be simple.

Next, with reference to FIG. 8, the outline of the wafer binding system,which includes means for supplying carrier plate 7 and wafer 6 to theaforementioned binding part and means for taking out carrier plate 7binding wafers 6 from the binding part, will be explained.

To begin with there is a carrier plate stock part 100. Carrier plate 7is carried in to this carrier plate stock part 100 by transportationmeans 102. Carrier plate 7 which is located in the carrier plate stockpart 100 is transported to washing apparatus 106 by transportation means104. In this washing apparatus 106 the washing is carried out forattaining the smoothness necessary for the binding surface of the wafer.Each carrier plate 7 can be located in an upright position in theaforementioned washing apparatus 106, and further can be successivelyfed into washing units 108, 110,112 where the washing is done by thewashing liquid of the container.

Carrier plate 7 which is washed by aforementioned washing apparatus 106,is sent to spin drying apparatus 114 and then rotated in theaforementioned spin drying apparatus 114. Water drops on the surface areremoved by the centrifugal force which occurs during the rotation.

Dried carrier plate 7 in aforementioned drying apparatus 114 is sent toheating apparatus 118 by transport means 116 and dried. This heatingapparatus 118 has three heating units 120,122,124. By these, successiveheating is carried out and the surface temperature is caused to rise toa level which is suitable for the binding. Each transport of a carrierplate between heating units 120 to 124 is done by transport means 126provided on both sides of heating apparatus 118.

Carrier plates 7 which are in aforementioned heating apparatus 118 aresent to binding part 128 which was explained in detail before. Reversingpedestal 130 receiving temporarily carrier plate 7 before binding andreversing pedestal 132, which receive temporarily carrier plate 7 afterbinding are provided respectively in the front and back of binding part128.

Following the arrangement sequenced of aforementioned binding part 128and reversing pedestals 130, 132, carrier plate transporte 134 isprovided thereafter. By this carrier plate transporter 134, thetransportation of carrier plates 7 between these machines is attained.

Hereinafter, an explanation on the means transporting wafer carrier 5,which is loaded with wafers 6 to aforementioned binding part 128, isgiven.

Furthermore, there is centering apparatus 140, washing apparatus 142,wax coater 144, hot bake apparatus 146 and position alignment apparatus148 for aligning the position of OF (orientation flat). Centeringapparatus 140 aligns the position of each wafer 6 supplied in fixedorder on the basis of their quality data, so that they are positionedconcentrically in line on the equipments 141 to 148. After being washedby washing apparatus 142, positioned aligned wafers 6 are coated by waxcoater 144 with the binding material (wax). Then, ingredients such asorganic solvents are removed by heating the wafers by means of hot bakeapparatus 146. Wafers 6 which have past the hot bake apparatus 146 arealigned at fixed orientation in OF position alignment apparatus 148.Furthermore, there are transport means 150 for transporting wafers 6between each of the aforementioned apparatuses.

Position aligned wafers 6 in OF position alignment apparatus 148 are puton wafer carrier 5 in wafer setting apparatus 152. Wafer carrier 5 isplaced on wafer carrier holder 154 and put on wafer setting apparatus152 by waver carrier transporter 146. Wafer 6 is set from OF positionalignment apparatus 148 to wafer carrier 5 placed on wafer settingapparatus 152 by wafer setting robot 158. Proceeding like this, wafercarrier 5, where wafer is set in fixed position, is forwarded to waferbinding part 128 by wafer transporter 156 and sent to cooling apparatus160 after being bonded to carrier plate 7.

Aforementioned cooling apparatus 160 consists of first, second and thirdcooling units 162,164 and 166. By a successive transfer between them,gradual cooling is carried out. Carrier plate 7, which is cooled down toroom temperature while passing through cooling apparatus 160, isforwarded to the next polishing process (not shown in the figure) bydelivering apparatus 168.

In the following, the construction of carrier plate stock part 100 isexplained with reference to FIGS. 9-11.

A pair of fixed frames 180 are provided in line with the arrangementdirection of carrier plate 7 (in direction of arrow a in FIG. 8).Between these fixed frames 180, a pair of rails 182 are provided. Onthese rails 182 a moving frame 184 is provided, which is movable alongthe length direction of rails 182. On this moving frame 184 a verticalmovement part 186 is provided which is able to move up and down invertical direction. Vertical movement part 186 is driven up and down bythe pneumatic machine (not shown in the figure) provided inside movingframe 184. At aforementioned fixed frame 180 and vertical movement part186, carrier supporting members 188,190 are provided respectively andtherein a plurality of notches 192 are provided for supporting carrierplate 7.

Carrier plate 7 supported by carrier supporting member 188 ofaforementioned fixed frame 180 is moved from one notch 192 consecutivelyto adjacent notches 192 according to the movement of moving frame 184and vertical movement part 186 as described hereinafter.

1. Since under normal conditions vertical movement part 186 is in thelowered position, shown in FIG. 9, carrier plate 7 is supported bycarrier supporting members 188 of the fixed frame 180. As shown if FIG.10(a) carrier supporting members 188, 190 are positioned in completealignment with respect to notches 192.

2. When vertical movement part 186 is lifted, carrier supporting member190 lifts carrier plate 7 and carrier plate is lifted as indicated bythe dotted line in FIG. 9.

3. When in this elevated condition, moving frame 184 moves in thedirection of arrow b, as indicated in the figure, carrier supportingmember 188,190, as indicated in FIG. 10(b), is dislocated at a distance11 which corresponds to the arrangement interval of notch 192.

4. When in this position vertical movement part 186 is lowered, carrierplate 7, which is supported by supporting member 197, is supported bycarrier supporting member 188.

5. When moving frame 184 is moved in the direction of arrow as indicatedin the figure, after vertical movement part 186 is lowered, thepositioning of the notches of carrier supporting parts 188,190 iscompleted and becomes the next operatory condition of the movement.

By repetition of the aforementioned movement, carrier plates 7 areforwarded one after the other to the next process by moving always at adistance equal to arrangement interval 11 of notch 192.

Next, the construction of the washing apparatus 106 is explained byreferring to FIGS. 11-13.

In washing apparatus 106 three washing drums 108, 110,112 are provided.In the lower part of each washing drum 108,110,112 turning rollers 202and 204 are provided, and by means of these rollers 202, 204 carrierplate 7 is supported from the beneath. Turning roller 202 rotates bymeans of a force generated by motor 206 and transmitted via belt 208:turning roller 204 is supported so that it can rotate freely accordingto the rotation of carrier plate 7. Inside washing drums 108, 110,112 acircular rotating brush 201 is provided. Since this circular rotatingbrush 210 is driven by the driving motor (not shown in the figure), bycontacting and rotating the surface of carrier plate 7, this surface iswashed. Furthermore, inside washing drums 108, 110, 112 a brush 212 isprovided which contacts the outer circumference of carrier plate 7. Inthe case of the preferred embodiment, the washing is done with analkaline washing liquid in washing drums 108 and 110. In washing drum112 washing is carried out by clear water, though kind and combinationof the washing liquid is not limited thereby. In the preferredembodiment, the upper part of washing drums 108, 110 are connected byconnection pipe 214.

The rotating body containing turning rollers 202, 204 and rotating brush210, all provided in aforementioned washing apparatus 106, is maintainedby a bearing penetrating the wall of washing drums 108, 112. Thisbearing is sealed and therefore prevented from leaking. The constructionof the bearing part is explained by referring to FIG. 13, which shows anexample of a washing drum 108.

Also in the figure, axis 211 which supports turning roller 204 isprovided. On the outside of washing drum 108 flange 212 is installed. Onthis flange 212 bearing 213, which supports aforementioned axis 211 forfree rotation, is provided. At the inside of aforementioned bearing 213an oil seal 214, sealing the gap between the inner circumference offlange 212 and the outer circumference of axis 211, is provided. At theinside of aforementioned oil seal 214 a nearly ring shaped cover 215 isinstalled. Between this bearing cover 215 and aforementioned oil seal214 a gap is provided which is parallel to the direction of the axis.Between the inner circumference of bearing cover 215 and the outercircumference of axis 211 an extremely small aperture in radialdirection is provided. In the aforementioned cover 215, a hole 216directed in a radial direction is provided. By normally pouring theliquid (normally clear water, washing liquid) into bearing cover 215 viathe hole 216, it becomes possible to exclude alien substances, occurringbecause of contact between the aforementioned oil seal 214 and axis 211,from getting to the outside of washing drum 108.

The charging and decharging of carrier plate 7 to the aforementionedapparatus 106, and the movement of carrier plate 7 between washing drums200, is carried out by transport apparatus 104. This transport apparatus104 is explained with reference to FIGS. 14 and 15.

At the outer part of the aforementioned washing apparatus 106, rails 220are provided which follow the arrangement line of washing drums 108,110,112. On this rail 220, moving frame 222 is provided. Furthermore,vertical movement frame 224 is provided on moving frame 222. To thisvertical movement frame 224, four carrier plate transport arms 226 areattached. Between these carrier plate transport arms 226 intervals 12are provided, whereby this interval is equal to the respective intervalsbetween washing drums 108,110,112. At the end of every aforementionedcarrier plate transport arm 226, a protrusion 228 is provided and has anouter diameter such that it loosely slips into a hole formed in thecenter of the carrier plate. The aforementioned protrusion 228 can beinserted into and withdrawn from the hole in carrier plate 7 by movingframe 222 in the direction of or opposite the direction of arrow a, asshown in FIG. 14. When inserting protrusion 228 into the hole of carrierplate 7, by means of vertical movement frame 224 and moving frame 222,it becomes possible to forward carrier plate 7 to containers 108,110,112 and also withdraw it from containers 108, 110, 112 as well.

Transport apparatus 104, which is constructed as explained above,operates and transports carrier plate 7 as described hereinafter.

When carrier plate transport arm 226 is lifted under the condition asshown in FIG. 14, carrier plate 7 rises to the position as indicated bythe dotted line in FIG. 15 from the position indicated by the solid linein FIG. 15 (position where it is soaked in the liquid of washingcontainer 108). Under this rising condition, moving frame 222 is causedto move over the distance 12 in direction of arrow a, indicated in FIG.14 and carrier plate 7, located at the very bottom in FIG. 14, is placedon washing container 108. Carrier plate 7 is then lifted up from washingcontainer 108 (shown at the very bottom of FIG. 14) and is placed onwashing container 110 (second washing container from the bottomindicated in FIG. 14), carrier plate 7 which is lifted up from washingcontainer 200 is placed on washing container 112 (washing containershown on the very top in FIG. 14), and finally carrier plate 7, which islifted up from washing container 112, is forwarded to the carrier platereceptor (explained in detail hereinafter) for the next process (spindrying apparatus 114).

In this position, when vertical movement frame 224 is lowered, allcarrier plates 7 are placed into washing container 108, 110,112 (carrierplate 7 is moved from the position indicated by the dotted line FIG. 15to the position of the straight line). After vertical movement frame 224has been lowered, and when moving frame 222 is moved slightly more thanthe dimension of protrusion 228, protrusion 228 is withdrawn fromcarrier plate 7. After having lifted vertical movement frame 224 at thiscondition, and when it is moved for a distance 12 is opposite directionof arrow a shown in FIG. 14, the preparation condition for the nexttransport action is completed. By repeating the aforementionedprocedure, carrier plate 7 can be forwarded step by step between washingcontainers 108, 110, 112 in the direction of arrow a. When carrying outthe transportation between washing containers 108, 110, 112 by such aprocedure, no carrier plate 7 is left out, and accordingly, such thingsas re-adhesion of alien material cannot occur when drying.

Hereinafter, an explanation on the spin drying apparatus 114 is givenwith references to FIGS. 16 and 17.

A carrier plate receptor 240, supported by a pair of arms 242, isprovided. In the carrier plate receptor 240, carrier plate supportingmembers 244 are provided for supporting carrier plate 7. Theaforementioned arms 242 can rotate in a vertical plane, around axis 246by which they are supported and are driven by pneumatic cylinder 248.The aforementioned carrier plate supporting members 244 are each movedforward and backward by neumatic cylinder 250, and so can be moved inapproaching or separating direction. Furthermore, carrier plate receptor240 is positioned between supporting positions of carrier plates 7 inaforementioned washing container 112 at an interval equal to shiftstroke 12 of transport means 104.

A turntable 252 is driven by motor 254 whereby the axis of the rotationis axis 256. The aforementioned turntable 252 is of plane shape asindicated in FIG. 16. In the position corresponding to the notch part258 of turntable 252 vertical movement part 260 is provided. Thisvertical movement part 260, driven by pneumatic cylinder 262, passesnotching part 258 of aforementioned turn table 252, and can move upwardand downward as indicated in FIG. 17. Furthermore, transport means 116and flap 264 are provided in the neighborhood of aforementioned spindrying apparatus 114. This flap 264, driven by pneumatic cylinder 230,is attached to the lower end of arm 268 which is supported such that itcan rotate around axis 266.

In transportation means 116, a disk 274 having a notch as indicated inFIG. 18 is provided at the lower end of arm 272 which rotates round axis270.

There is a clear water supply pipe 276 supplying hot clear wateraccording to the demand to the surface of carrier plate 7 on dryingapparatus 114. This clear water supply pipe 276 can be moved to aposition above turntable 252 and also be removed from this position byrotating it around axis 278.

The action of the above mentioned drying apparatus 114 is explained asfollows:

1. Carrier plate 7 taken out of the third washing unit 112, belonging towashing apparatus 106, by transportation means 104, has been arranged atthe upper parts of the carrier-plate support material parts 244 as shownin FIG. 17; moving along distance 12 of transportation means 104.

A pair of carrier plate support material parts 244 are prepared in amutually separated condition. In this situation carrier plate 7 isinserted in a pair of carrier-plate support material parts 244,according to the items brought down by the transportation apparatus.Afterwards, when the carrier-plate support material parts 244 approachmutually, they are supported by carrier plate 7 inbetween.

2. When the pneumatic cylinder 248 is extended, arm 242 rotatesclockwise as shown in FIG. 17, and carrier plate 7 is arrangedhorizontally in the upper part of turntable 252.

3. Ascending and descending parts 260 rise and support carrier plate 7from beneath. Furthermore the carrier plate support material parts 244separate from each other and carrier-plate 7 is placed on turntable 252.

4. he cleaning-pipe 276 rotates and is placed on the top of turntable252; after supporting the cleaning process of the surface ofcarrier-plate 7, the cleaning-pipe 276 is returned to its initialposition.

5. After lowering cover 264 to a position where there is only a shortdistance to the surface of carrier-plate 7, turntable 252 rotates for afixed interval: drops of water on the surface of carrier-plate 7 areremoved by centrifugal force. Moreover, along with the rotation ofturntable 252, air is blown down onto the surface of carrier plate 7.Furthermore the rotation time of turntable 252 can be arbitrarily fixedby means of the timer (not shown in the figures) provided in theelectric power supply circuitry of motor 254. Moreover, along with therotation of turntable 252, the surface of carrier plate 7 is dried byair. Due to this drying air, the adherence of water drops, scatteredaround the periphery due to the centrifugation, to the carrier plate 7is prevented. In addition, the expelled drying air is set up to theequal or higher temperature than that of the liquid used in the washingprocess (80° C.). In order to prevent the temperature fall of carrierplate 7 due to spin-drying.

6. When the rotation of turntable 252 as well as the expulsion of thedrying air are completed, cover 264 rises up to the position indicatedby the dotted line as shown in FIG. 19. Furthermore by means of theascending and descending parts 260, carrier-plate 7 is lifted to aposition above turntable 252.

7. Arm 272 rotates and is arranged into the same position as turntable252. When the ascending and descending parts 260 are put down,carrier-plate 7 is placed on the tip of disk 274 of arm 272.

8. Arm 272 rotates and, as shown in FIG. 18, transports carrier-plate 7to the top of the heating unit 120. After the completion of procedures 1through 8, the process returns to the above mentioned procedure 1 andthe spin drying disposal of the next carrier-plate 7 begins.

Next, heating apparatus 118 as well as transportation means 126 will beexplained in relation to FIGS. 20 through 24.

The heating units 120 through 124 , which comprise heating apparatus118, are mutually installed in the space 13. Due to the electric heatingby heating units 120 through 124 of the disk upon which carrier-plate 7rests, the temperature of carrier-plate 7 gradually increases from roomtemperature to a temperature appropriate for bonding. Furthermore anaxle 280 is provided in the center of respective heating units 120through 124 as shown in FIG. 24. The tip of this axle 280 is inserted inthe center of carrier-plate 7 which rests on top of heating units 120through 124. The above mentioned axle 280 is moved up and down, as shownin FIG. 21, driven by means of pneumatic cylinders 282 through 286 whichrespond to the heating units 120 through 124. Due to the rising of axle280, carrier-plate 7, supported by axle 280, is then lifted up above thesurface of heating units 120 through 124. Axle 280 descends andcarrier-plate 7 comes into contact with heating units 120 through 124.

A set of tracks 288 which make up the transportation frame are providedon both sides of heating apparatus 118. Transportation frame 290 issupported by transportation members 292, which transport carrier-plate7, lying on top of heating units 120 through 124, over the intervalsbetween the respective heating units.

The mechanism of the aforementioned transportation members 292 isconstructed as follows:

For transportation frame 290 two pairs of bearings 294 are set up, whichexert an influence on the support of a pair of axles 296. At the tip ofeach axle 296, crank arms 298 are installed respectively. At the tip ofthese crank arms 298, the above mentioned transportation members 292 areconnected in a way that rotation is possible with axle 300 as thecenter. Furthermore crank arm 302 is arranged on one basic side of axle296. Crank arm 302 is connected to pneumatic cylinder 304 . Thecontraction and expansion of pneumatic cylinder 304 allows axle 296 torotate. Due to this contraction and expansion, the aforementioned pairof transportation frames 290 approach to a position where they can pileup with carrier-plate 7 or where they can detach from it. Moreover, dueto the contraction and expansion of rod 308 of power-cylinder 306, themovement to the left and right ranging to space 13 is made possible.

Next, the transportational movement of carrier-plate 7 by transportationmeans 126 will be explained below.

1. When receiving carrier-plate 7, the transportation members 292 are ina mutually separated condition and axle 280 is lowered and ready forfurther movements.

2. When carrier-plate 7 is transported to the top of heating units 120,due to the rotation of arm 272, axle 280 rises and carrier-plate 7 isinserted so that it is supported by axle 280.

3. When axle 280 is lowered, carrier-plate 7 is placed on top of heatingunits 120 through 124 and heated.

4. When carrier-plate 7 is heated to a predetermined temperature byrespective heating units 120 through 124, axle 280 rises and lifts eachrespective carrier-plate 7. Due to the rise of axle 280 the underside ofeach carrier-plate 7 is set up to a higher position than the surface oftransportation members 292.

5. The transportation members 292 approach each other reciprocally and,as shown in FIG. 20, are arranged at a level position on the outerperiphery of each carrier-plate 7.

6. When one of the axles 280 descends, a carrier-plate 7 on top of oneof the respective heating units 120-124 is supported by the respectivetransportation members 292.

7. When rod 308 of power-cylinder 306 contracts, transportation frame290 crosses space 13 and carrier-plate 7 on top of heating part 120moves to the top of heating part 122; while carrier-plate 7 on top ofheating part 122 moves respectively to the top of heating part 124.

8. When one of the axles 280 rises, carrier-plate 7 is taken up. Inaddition, the transportation members 292 become mutually separated.

Similar to the three processes mentioned above, with the lowering ofeach axle 280, a carrier-plate 7 is placed on top of one of respectiveheating units 120-124, the carrier plate 280 is heated, and theaforementioned process is repeated.

The aforementioned axle 280, provided in the final heating unit 124, inaddition to accompanying the carrier movement of the aforementionedcarrier plate 7, is employed in adjusting the temperature of the carrierplate 7. For example when the carrier plate 7 is placed on the top ofthis final heating unit 124 for a long period of time, depending on thereason for stagnation, etc. of the binding process occurring within thebinding unit 128, the temperature will rise to an excess. In order toprevent this kind of temperature rising, the heating unit 124 can adjustits own temperature according to its heat capacity, but in this case theproduction of a time lag in the temperature control cannot be avoided.In this example, according to the rising of the axle 280 provided in theheating unit 124, the carrier plate 7 can be lifted from the heatingunit 124. Namely, when the carrier plate 7 is superheated, thetemperature of the carrier plate 7 can be controlled by means ofcontrolling of the rising of the axis 280.

With the aforementioned binding unit 128 as the center, a coolingapparatus 160 is provided at a location symmetrical to the position ofthe heating apparatus 118. Cooling units 162-166 disclosed in thiscooling apparatus have a similar organization to the heating units120-124. Each of the cooling units 162-166 is designed in a manner suchthat the temperature is gradually lowered according to the flow of theheating medium in the interior of the unit. In this way, the carrierplate 7 placed on top of this unit is gradually cooled from bindingtemperature to room temperature. Additionally, on the side of thecooling apparatus a carrier means 126 is provided which, in the samemanner as the aforementioned heating apparatus, conveys the carrierplate 7 over the distance 1₃ between each cooling unit 162-166.Furthermore, an imprinting machine 310 is provided for attaching anidentification mark to the carrier plate 7.

In the following, the binding unit 128 and the carrier platetransportation machine 134 will be explained with reference to FIGS. 25through 27.

This carrier plate transportation machine 134 conveys the carrier plate7 along the direction of the aforementioned heating apparatus 118,binding unit 128 and cooling apparatus 160. On top of a railway 312 areprovided first and second moving frames 314, 316 respectively. In eachof these moving frames 314, 316 first and second vertical movementframes 315, 317 are provided. In each of these vertical movement frames315, 317 arms 318, 320 capable of rotation are provided. At the edges ofthese arms 318, 320 are provided first and second adhesive means 322,324 which are inserted into the lower parts of the carrier plates 7 andthus adhere to the lower surface. In addition, the aforementioned movingframes 314, 316 run along the lines of the previously mentioned railwayand are able to move in both left and right directions, in both FIGS. 25and 26, through the rotating of provided first and second feed screws326, 328 by each respective driving motor 330, 332.

Organized in the above mentioned manner, the carrier platetransportation machine 134, through first adhesive means 322, adheres tothe carrier plate 7 which has been transported as far as heating unit124 of the heating apparatus 118. The carrier plate 7 is turned about inaccordance with the rotating of axle 318. After the prepared bindingsurface is turned downward, the carrier plate 7 can be placed on top ofthe pedestal of the binding means 128.

Additionally, the carrier plate 7 bonded to the wafer, is bonded andlifted up from the top of pedestal 4 by means of second adhesiveapparatus 324. According to the rotation of axle 320, the carrier plate7 is turned about and once the prepared binding surface is turneddownward, the carrier plate 7 can be placed on top of the pedestal ofbinding means 128.

The aforementioned wafer transportation machine 156, as shown in FIG.28, is designed so that the adhesive means, provided at both ends of therotating arm 342 with axle 340 as the center, is capable of moving bothupward and downward respectively by means of the pneumatic cylinder 346.Additionally, the aforementioned pedestal 4, wafer setting apparatus 152and wafer carrier holder 154 are arranged along the lines of the arc ofthe rotating locus of the aforementioned arm 342 (as shown in part C ofFIG. 8). Therefore, by means of the aforementioned arm 342 and the upand down movement as well as the repetition of the adhesive opening ofthe adhesive means 344, the carrier plate 7 can be transported over thedistance between pedestal 4, wafer setting apparatus 152 and wafercarrier holder 154.

The aforementioned wafer carrier holder 154 is designed in a manner suchthat a large number of rollers 352 are provided on top of the supportingbody 350 maintaining wafer carrier 5. The wafer carrier 5, by means ofthese rollers 352, is able to transport inside and outside of the movingrange of the aforementioned arm 342. Furthermore, a a driving forceapparatus has been placed inside of a portion of the above mentionedroller 352 (figure not included), thus the roller is able to rotate byitself. The other rollers 352 are designed to rotate according to themovement of the wafer carrier 5.

In the following, the organization of the line supplying the wafer 6 tothe wafer setting apparatus 152 will be explained.

In this line the wafer is supplied in each batch using a previouslyestablished system according to the data results obtained for suchqualities as thickness, etc. Additionally, in this line, the wafersurface with the CVD (Chemical Vapor Deposition) coating is turnedfacing upward, and the wafer 6 is then transported.

The movement of the wafer 6 over the intervals between centeringapparatus 140, cleaning apparatus 142, wax coater 144, hot bakingapparatus 146 and OF position alignment apparatus 148 is carried bymeans of the working beam 360, shown in FIGS. 29 and 30.

Working beam 360 has a plurality of support plates 362, as shown in FIG.29. In the intervals between the support plates 362, arrangement spaces14 and equivalent spaces 14 for centering apparatus 140, washingapparatus 142, wax coater 144, hot baking apparatus 146, and OF positionalignment apparatus 148 are provided. The connecting units of the wafers6 on top of these apparatuses are designed so that that they can belifted from the lower base parts. The aforementioned working beam 360 issupported by a vertical movement frame 364 through which upward anddownward motion is possible, and is driven upward and downward by meansof an pneumatic cylinder 366. Additionally, the aforementioned verticalmovement frame 364 is supported such that movement in both the left andright directions in FIG. 8 is possible. As well, this vertical movementframe 364 is moved right and left by means of a feed screw 370 driven bya motor 368.

The centering apparatus is shown in FIG. 31. The vertical movement body380 moves upward and downward by means of the pneumatic cylinder 382 andin this way the vertical up and down moving of a wafer 6 placed on topof this body is possible. In a position alignment plate 384, there areprovided a first step 386 and a second step 388. According to a standardwafer to be treated by this centering apparatus, these steps 386 and 388are fixed to the dimensions of the wafer's inner diameter, slightlysmaller than the outer diameter. Additionally, at the upper parts ofthese aforementioned steps 386, 388 tapered portions 390, 392 areprovided in order to guide the wafer to these steps. In this centeringapparatus, the wafer is received when the vertical movement body 380 isin the elevated position. Following this, the wafer is guided to step386 or 388 by the either of the aforementioned tapered parts 390, 392according to the descent of the vertical movement body 380. Thepositioning of the wafer is determined according to the followingcleaning apparatus and wax coater.

In the following, the washing apparatus will be described according toFIG. 32. In the figure a turn table 400 is provided which is designed torotate, driven by the motor 402. The aforementioned turn table 400 andmotor 402 are supported by a vertical movement frame 404. This verticalmovement frame 404 is supported such that it freely moves upward anddownward and is driven by means of an pneumatic cylinder 406.

At the upper part of this turn table 400 are provided two nozzles: thefirst nozzle 408 shoots the washing liquid out onto the wafer 6 at ahigh pressure, while the second nozzle 410 adds ultrasound wave energyto the washing liquid and blows it against the wafer 6. First nozzle 408and second nozzle 410 are supported by free rotating arms 412 and 414.The aforementioned arms 412, 414 are supported by axles 416, 418 as thecenters such that the arms are capable of rotation. The pulley 420,provided at the lower portions of the aforementioned axles 416, 418, isdriven by a motor such that the cleaning liquid can be blown out over awide range. However, the axle 416, driven by the motor, as well as thepulley are not shown in the figures. The circumference of the abovementioned turn table 400 is enclosed by a lower portion cover. Thesuction piping 426, connected to the lower portion cover 424, isdesigned to remove air and drops of water inside of the lower portioncover. At the upper part of the aforementioned lower portion cover 424,an upper portion cover 428 and an upper lid 430 are provided. During thewashing of the wafer 6, this upper portion cover 428 is in a loweredstate, in order to prevent the scattering of water drops and dustparticles. In addition, during the cleaning of the wafer 6, the upperlid 430 is brought to the raised position in order to avoid the adhesionof the cleaning liquid spray.

In this cleaning apparatus, first and second nozzles 408, 410 eachrotate together with the turn table 400: during rotation, these nozzlesjet out washing liquid onto the wafer 6 which lies o top of the turntable. The washing liquid is jetted out from the first nozzle 408 at aflow rate of 0.5-2.0 liters/ minute under a pressure of 100-300 kg/cm².The high pressure of the washing liquid mainly removes materials whichare loosely attached to the surface of the wafer. If the pressure of thewashing liquid propelled out of first nozzle 408 is below a minimumfixed value, the washing is insufficient, however if a maximum fixedvalue is exceeded, then damage is inflicted to the surface of the wafer.The washing liquid furnished with 500-1000 KHz wave oscillations isjetted out of second nozzle 410 at a flow rate of 0.5-3.0 liters/minute.Additionally, it is enough that the pressure of the washing liquidjetted out of second nozzle 410 is sufficiently less than that of thefirst nozzle 408. This washing liquid furnished with the high frequencyoscillation energy removes fine particles on the surface of the wafer.The washing liquid supplied from second nozzle 410, through theemployment of high frequency oscillation energy, has a high washingability, thus the pressure of the washing liquid jetted out of firstnozzle 408 may be comparatively small such that there is very littlechance of damage to the wafer surface by this pressure. A fear ofdamaging the wafer surface exists if the period of the wave oscillationsadded to the aforementioned washing liquid is lower than a minimum fixedvalue; however, when a maximum fixed value is exceeded, the oscillationsare reduced, and detergency is lost.

After the supplying of the aforementioned washing liquid is ceased, theturn table 400 continues rotating. At the same time as the removal ofthe washing liquid from the wafer surface, the upper lid 430 is loweredto the wafer surface, and the wafer surface is dried by blowing inertgas against it.

Between the aforementioned washing apparatus 142 and the wax coater 144,a space that is two times the normal space 2×14 is provided.Consequently, in the washing apparatus once the washed wafer 6 has beenplaced into the space between the washing apparatus 142 and the waxcoater 144, the wax coater is ushered in.

The wax coater 144 will now be explained using FIG. 33.

In the figure, turn table 440 rotates, driven by means of a motor 442. Acover 444 is provided around the circumference of the turn table 440.Connected to this cover 444 is a suction duct, which is designed toremove by suction such things as air from the inside of the cover.

A lid 448 is provided above the aforementioned turn table 440. This lid448 is either supported by the pneumatic cylinder 450 in the upraisedposition shown in the figure, or can be moved into the lowered positioncovering the upper opening of the aforementioned cover 444.Additionally, on the aforementioned lid 448, two wax supply nozzles areprovided. These wax supply nozzles 452 are designed to supply wax to thesurface of the wafer 6 which lies on top of the aforementioned turntable 440. Furthermore, the above mentioned motor 442 moves upward anddownward by means of the pneumatic cylinder 454, and is supported by thevertical movement frame 456: this motor 442 is designed so that it iscapable of moving upward and downward together with the aforementionedtime table 440. In the aforementioned turn table 440 is provided an endconnection 458, connected to the vacuum source (not shown in thefigures). By employing this vacuum source, supplied from the endconnection, on the upper surface of the turn table 440, the wafer 6 isglued to the upper surface of the turn table 440.

The aforementioned hot baking apparatus 146 supports the wafer 6 whichlies on top of the vertically mobile table: through the heating of thisabove mentioned table, the organic solvents inside of the wax areremoved.

The wafer 6 processed by both the wax coater 144 and hot bakingapparatus 146 is guided to the OF position alignment apparatus 148 bymeans of the working beam 360. Using carrier means 150, the wafer isfurther guided to the wafer setting apparatus. In the following, each ofthe above mentioned apparatuses will be described with reference toFIGS. 34 and 35.

In the OF position alignment apparatus 148, a turn table 460 isprovided. This turn table moves upward and downward by means of anpneumatic cylinder 462 and rotates by means of motor 464. Additionally,an OF detector 466 is provided around the periphery of the turn table460. This OF detector decides the position of the OF portion of thewafer 6, depending on the detection of whether the light beam isintercepted or not. Depending on this decision, by controlling thestoppage of the motor 464, as shown in FIG. 34, OF can be stopped at apredetermined angle.

In the carrier means 158 a rotating body 472 is provided which rotatesby means of a motor 470. On top of this rotating body 472, an arm 474 isprovided which is capable of moving radially. This arm 474 can alsoextend in the direction of the above mentioned turn table 460.Therefore, when the aforementioned turn table 460 is in the upraisedposition (the arm 474 may be relatively lowered), the arm 474 isextended and then by lowering the turn table 460 (the arm 474 isrelatively raised), the wafer 6 is placed on top of the arm 474. Withthe wafer 6 placed on top, the arm 474 is then rotated 180 degrees andswung towards the wafer setting unit 156. In this wafer unit, a turntable 480 is provided upon which a wafer carrier 5 is placed. Accordingto the driving of this turn table 480 by a motor 482, the wafer storagecavity of the wafer carrier 5 is brought to a position on line with theabove mentioned rotating body 472.

In between the above mentioned carrier means 158 and the wafer settingunit 152, a wafer guiding apparatus 484 is provided. This wafer guidingapparatus 484 is driven by means of a rotary coil 486 and can be movedto the position of the solid line as well as the position of the dottedline, as shown in FIG. 34. Specifically, when the above mentioned arm474 is lowered, the wafer 6 is guided to a predetermined position on topof the wafer carrier 5, shown by the solid line in the figure.Additionally, when trying to adhere the wafer carrier 5 by means of theadhesive means 344 provided on the arm 342 of the aforementioned wafermovement machine 156, the wafer carrier is arranged to a positionseparated from the movement path of the above mentioned adhesive means344, namely to the position of the broken line shown in the figure.

The aforementioned turn table 480 is arranged in a position on top ofthe rotation tracks of the arm 342 of the above mentioned wafer movementmachine 156. By means of this arm 342, both the carrying in of the emptywafer carrier 5 and the carrying out of the wafer carrier 5 with thewafer 6 in the predetermined position are performed.

The movements of the wafer binding apparatus formed in the above mannerwill now be explained.

The carrier plates 7 are stacked vertically inside of the carrier platestock unit 100. The carrier plates 7 housed inside of the carrier platestock unit are fed to the washing apparatus 106, one at a time, by acarrier means 104 and are transported to each step of the washing means106 during the washing process. The binding surface of the washedcarrier plate 7 is then turned upward and fed to a drying apparatus 11:once the water portion is removed, the carrier plate 7 is fed to theheating apparatus 118. Once fed to the heating apparatus, the carrierplate 7, by means of the carrier means 126, is taken through each stepof the drying process. The carrier plate 7, once it has reached the lastheating unit 124, is then picked up by a carrier plate transportationmachine 314: the carrier plate 7 is then turned about and after thebinding face has been turned downward, is made to wait at the side ofthe binding machine 128.

Meanwhile, once the position of the wafer has been set by the centeringapparatus 140, the wafer 6 is washed by means of the washing apparatus142 and coated with binding agent by means of the wax coater 144. Thesolvent is then evaporated in the hot baking apparatus 146, and afterthe position of the wafer 6 is set by the OF position alignmentapparatus 148, the wafers are fed, one at a time, to the wafer settingunit 152 by means of the wafer setting robot 158. Additionally, at thesame time as this feeding, the transportation of other wafers is beingcarried out over the intervals between the aforementioned centeringapparatus 140, washing apparatus 142, wax coater 144, hot bakingapparatus 146 and OF position alignment apparatus 148.

The wafer carrier 5 is prepared on top of the wafer carrier holder 154and then fed to the aforementioned wafer setting apparatus by means ofthe wafer transportation machine arm 342. In the wafer settingapparatus, the wafer 6 is inserted into the wafer carrier 5, inaccordance with the mutual execution of both the feeding of the wafer 6,by means of the aforementioned wafer setting robot 158, and the rotationto the predetermined angle of the turn table 480.

When a fixed number of wafers are inserted into the wafer carrier 5, thewafer transportation machine 156 feeds the wafer carrier 5 to thebinding apparatus 128. After the carrier plate 7 has been fed to thebinding apparatus by means of the carrier plate transportation machine314, the wafer carrier 5, wafer 6 and carrier plate 7 are arranged inthe predetermined positions as shown in FIG. 2. In this arrangement, thebinding apparatus 128 moves and the wafer 6 is bonded to the lowersurface of the carrier plate 7.

After binding, the carrier plate transportation machine 316 attaches tothe inner side of the carrier plate 7 and lifts the carrier plate 7:after the surface bonded to the wafer 6 is rotated so that it is facingupward, the carrier plate is placed on the first cooling unit 162 of thecooling apparatus 160.

In the cooling apparatus 160, the carrier plate 7 is slowly cooled whilebeing transported, by means of the carrier means 126, to each of thecooling units 162, 164 and 166. In the cooling apparatus 160, after anidentification mark is attached to the carrier plate 7, which is cooleduntil a predetermined temperature is reached, is sent to the polishingprocess.

The carrier and washing means, in the above described apparatus, are notjust restricted to the given examples, and can, of course, be modifiedaccording to the dimensions and resources of the wafer.

The apparatus in the above mentioned example, wherein in a bindingapparatus the wafer is pressed up against the lower surface of thecarrier plate which has been turned downwards, is capable of feeding thewafer and carrier plate to the ultimate binding position for thisbinding. Therefore, the binding apparatus can essentially preserveresults such as the prevention of air bubbles on the binding surface andthe improvement of the wafer flatness by removing the particles on thewax coated surface of the wafer in addition to efficiently feeding thewafer and carrier plate to the binding apparatus.

What is claimed is:
 1. A wafer binding apparatus comprising:a bindingunit which binds said wafer to said carrier plate; a first carrier meanswhich supplies a carrier plate to said binding unit, a second carriermeans which supplies said wafer to said binding unit, and a thirdcarrier means which carries said carrier plate bonded to said wafer fromsaid binding unit, wherein said binding unit comprises: a carrier platesupport means which supports said carrier plate, a wafer support means,located on the under side of said carrier plate support means, whichsupports said wafer, and a wafer transportation means which raises saidwafer, supported by said support means, up until contacting the undersurface of said carrier plate, wherein in the interval between saidfirst carrier means and said binding unit, a rolling means is providedfor flipping the sides of said carrier plate.
 2. A wafer bindingapparatus according to claim 1 wherein the upper surface of said waferand said carrier plate to be bonded to the upper surface of said waferare placed under reduced pressure and after said wafer is raised andbonded to the under surface of said carrier plate, pressure is raised bysaid binding unit.
 3. A wafer binding apparatus according to claim 1wherein:said first carrier means transports said carrier plate with thesurface to be bonded to said wafer facing upwards, and said secondcarrier means transports said wafer with the surface to be bonded tosaid carrier plate facing upwards.
 4. A wafer binding apparatusaccording to claim 2 wherein:said first carrier means transports saidcarrier plate with the surface to be bonded to said wafer facingupwards, and said second carrier means transports said wafer with thesurface to be bonded to said carrier plate facing upwards.
 5. A waferbinding apparatus according to claim 1 wherein on the transportationpath of said second carrier means a washing means is providedcomprising:a first washing unit which shoots out onto the surface ofsaid wafer, at a high pressure, a washing liquid, and a second washingunit which adds high frequency wave oscillations to a washing liquid andthen shoots said washing liquid with added high frequency waveoscillations out onto the surface of said wafer.
 6. A wafer bindingapparatus according to claim 2 wherein on the transportation path ofsaid second carrier means a washing means is provided comprising:a firstwashing unit which shoots out onto the surface of said wafer, at a highpressure, a washing liquid, and a second washing unit which adds highfrequency wave oscillations to a washing liquid and then shoots saidwashing liquid with added high frequency wave oscillations out onto thesurface of said wafer.